Fibrosis is a process of forming fibrous connective tissue overly in an organ or tissue for reparation or reaction. Slight fibrosis of organ or tissue is called fibrosis, severe fibrosis can cause damage of tissues leading to organ scarring. Tissue fibrosis is not only in lung, liver, heart, kidney, and the like tissue, but in all the organs and systems of the human body, about 1/3 persons in the world are dead from tissue fibrosis and organ failure caused by it.
Nitrogen heterocyclic derivatives having anti-fibrotic effects were disclosed in patent application WO2014012360 and CN103570630, wherein the compound 3-(4-(dihexylamino)-3-fluorophenyl)-2,6-dimethylpyrimidin-4(3H)-one (compound I) can prevent or treat tissues fibrosis lesion in a human or animal.

Drug polymorphism is a common phenomenon in drug research, it is an important factor affecting drug quality. Various crystalline forms of the same drug have significantly different appearance, solubility, melting point, dissolution, bioavailability, and so on, also have different effects on stability, bioavailability and efficacy and so on. Therefore, the polymorphism problem of a drug should be considered overall in drug research.
Amorphism is a form in substance polymorphism phenomenon, it is an amorphous state. Various physicochemical properties and clinical efficacy characteristics of an amorphous drug are often different from those of a general crystalline drug. Therefore, a deep discuss for an amorphous substance is also important in polymorphism research of solid drugs.